1. Field of the Invention
This invention relates generally to a lifting apparatus, and in particular, it is an apparatus for lifting steel grates, manhole covers, drain covers and other similar structural members. Steel grates, such as those used for storm sewers, frequently weigh 500 pounds and upward, and because of their weight and unwieldy size, cause difficulty in lifting and removing same. Workmen have encountered considerable difficulty in using conventional equipment like crowbars and road machinery equipped with hydraulic accessories. Recuring damages to said equipment has been resultant.
It is necessary to remove a grate or manhole cover to work within the pipelines or drains below. However, there are often long periods of time between grate removals, which allow the weather, road dirt, ashes, salt, and other debris to form between the cover and framework, bonding same together. The present invention is designed to eliminate demolition of the framework, which is often damaged by other types of equipment on the market.
2. Description of the Prior Art
The prior art includes various devices for lifting manhole covers and the like. For example, in U.S. Pat. No. 4,250,769 issued to Gerald F. Herring is disclosed a pivoted adjustable lever with grab link. Herring's apparatus uses an adjustable hand lever having a vertically adjustable tripod base and adjustable fulcrum point and a grab link at the working end of the lever. U.S. Pat. No. 4,512,554 issued to Jacques Racine is disclosed a levering tool for lifting manhole covers. The tool comprises a base provided with anti-skidding elements formed of studs and a series of parallel plates, and a rigid and elongated power bar. The tool works to displace the cover by applying a small force on the free end of the power bar while maintaining the anti-skid base substantially stable. In U.S. Pat. No. 4,488,706 issued to Kazuhiko Kono is disclosed a manhole lifting hook comprising a lever rod having a load end, at least one roller rotatably mounted on the lever rod and rollingly movable at least in a back-and-forth direction, and a hook mounted on the load end for engaging the hook hole in the manhole cover. U.S. Pat. No. 4,365,925 issued to Sylvester A. Girtz discloses a manhole cover lifter comprising an elongated inclining lever with a handle at its upper end and a fastener at its lower end for attaching to the cover of the manhole. A depending strut intermediate the ends of the lever and a pair of wheels is mounted at the lower end of the strut and on a transverse axis forming a fulcrum for the lifting lever. U.S. Pat. No. 3,985,338 issued to Edgar R. Herrmann is disclosed a manhole cover lifter consisting of a long lever which at one end has a hook for engaging an opening through the manhole cover. A fulcrum is located relatively close to the end of the lever having a hook, so that when a workman places his foot upon the other end of the lever, he can pry the manhole upwardly for easy removal. U.S. Pat. No. 3,198,362 issued to Harold I. Berg is disclosed a relatively complex tool for lifting manhole covers. U.S. Pat. No. 4,482,182 issued to James W. Morensen and U.S. Pat. No. 2,846,259 issued to Ernest N. Sadler also discloses two other apparatuses for lifting manhole covers.